1. Technical Field
Embodiments of the present invention relate to the field of laser Raman spectroscopy-based safety inspection technology, and particularly to a protective device and a laser Raman safety inspection apparatus comprising the protective device.
2. Description of the Related Art
In prior art, a laser Raman spectrometer is usually adopted to inspect dangerous goods and perform substance identification, and, visible laser or infrared laser is used as its light source to irradiate a substance to be inspected to obtain Raman spectrum scattered by the substance. The Raman spectrum is only related to molecular structure of the substance to be inspected, and thus can be regarded as “fingerprint” information for identification of the substance to be inspected. Accordingly, through the Raman spectrum, structural information of substance can be obtained, which can determine category of the substance.
Visible laser or infrared laser will cause permanent damage to retina or other human tissues after reaching a certain power. So, when an apparatus with laser irradiation is adopted, its inspection device is required to satisfy safety requirements and should not cause laser irradiation damage to operator(s) on-site.
However, conventional apparatus has poor sealing performance, which results in leakage of visible laser or infrared laser, causing harm to human body.
In addition, since safety inspection apparatus is normally used in crowded areas including airports, rail transportation, customs, important venues and the like, it should have high detection efficiency, in order to avoid crowd congestion. Nevertheless, conventional apparatus has generally low efficiency.